Effect of high temperature on residual splitting strength of desert sand concrete

Abstract

AbstractThe ordinary medium sand can no longer meet the increasing demands of engineering projects. Construction costs can be reduced and the natural environment can be protected by rational use of the local desert sand. To evaluate the spalling and fire resistance of the concrete, the desert sand concrete (DSC) is heated to 100–800°C and then cooled for splitting tensile strength test. The test results indicate that with the increment of desert sand replacement rate (DSRR), the compressive strength of DSC increases first and then decreases. The maximum value is reached when DSRR is up to 40%. The presence of fly ash slows down the loss of splitting strength of concrete with the temperature increasing. The regression model is established to predict the functional relationship between the concrete splitting strength and temperatures under heating and air cooling conditions. The result shows that the predictions calculated by the formula are consistent with the experimental results. The formula can be employed as a constitutive relation of the computer model to evaluate the spalling and fire resistance of the DSC structure.